My wife's car is a 2007 530i and will hit 40k miles shortly (out of regular warranty/maintenance and into CPO). We've had the car for a few weeks now and likely plan to keep the car for several years. I want to get in and do any maintenance items which should be kept up with. I'm a 3-series owner and much more familiar with them and their weaknesses...

The first thing I want to hit are fluids: diff fluid, oil, coolant, brakes, and the big one: tranny fluid. Most of them should be pretty straightforward. I plan to put Redline in the diff. I guess I'll find out if the diff has a drain plug or not. As far as the tranny goes, I've read the long tranny fluid thread. I tried to negotiate a transmission fluid change when purchasing the car, and at first the dealer said yes, then the next day he said his mechanic didn't want to as it might void the warranty, and he just gave me cash off...

Has anyone experienced any issues changing the transmission fluid and the dealer claiming warranty problems? It makes me a little hesitant do the full change (ie the pan) as they'll know I changed it. However, with the CPO in place, I'd rather have the transmission decide to freak out on their dime. Regardless, I don't think at 40k miles there should be any danger of mysterious failure after a fluid change. Opinions?

Are there any other maintenance items or weak points I should keep an eye on? The 3-series is notorious for the cooling system failures (expansion tank/radiators/water pumps), but I haven't read the same here.

 

IMHO, I really don´t think you will have problems if you DONT change the tranny fluid at this point.

 

Ok, that sounds like a vote for change the fluid but not the pan/filter .

 

+1

 

Check to make sure no sign of transmission leaking. If you always get a smooth stop and never felt any hard shift, then the transmission should be fine. No need to change the transmission fluid.